Improvement in key-fasteners



R. MoOULLY. Key-Fastener.

No. 200,404. Patented Feb.1'9 l878.

ff itnessssw i' glnnenfnr N- PEi'ERS, PHOTO-LITHDGRAF UNITED STATEs PATENT OFFICE.

-ROBERT MoOULLY, OF PHILADELPHIA, PENNSYLVANIA.

IMPROVEMENT IN KEY-FASTENERS.

Specification forming part of Letters Patent No. 200,404, dated February 19, 1878; application filed March 9, 1877.

To all whom it may concern.-

Be itknown that I, ROBERT MoCULLY, of Philadelphia, in the county of Philadelphia and State of Pennsylvania, have invented certain new and useful Improvements in Locks and Keys; and I do hereby declare the followin g to be a full, clear, and exact description of the invention, such as will enable others skilled in the art to which it pertains to make and use it, reference being had to the accompanying drawing, which forms part of this specification, in which is represented a face view of a lock provided with my improvement.

The object of my invention is to provide simple and effective means for preventing a key from being turned in a look by burglars or other persons operating on the outside of the door to which said lock is attached.

My invention consists of a fastening device or dog comprising a spring-wire attached to the lock and a stud or catch fixed upon said wire, and adapted to engage automatically with a notched. key when the latter is in the lock, and at the moment that the bolt is projected, thus preventing. the key fi'onl being turned back or removed from the outside of the door.

Referring to the accompanying drawing, A designates an ordinary door-lock, to which is attached the elastic wire B, holding the catch b b. upper part of which is formed a semicircular guard or flange, D, having a recess or opening for the passage of the tooth b of the catch,

February, 1877.

ROBERT MGOULLY.

Witnesses:

- SAML. J. VAN STAvoREN, CHARLES F. VAN HORN.

0 represents the key-hole, around the 

